Haemophilus influenzae uses phase variation (PV) to modulate the activity of its defence systems against phage infection. The PV restriction–modification (R-M) system HindI, main infection and incoming chromosomal DNA in H. Rd, is driven by changes pentanucleotide repeat tract within coding sequence hsdM gene influenced lack Dam methylation. Phase-variable resistance/sensitivity correlates with lipooligosaccharide (LOS) structure occurs slippage tetranucleotide repeats lic2A , for a step...

Haemophilus influenzae Rf 232, showing the phenomena of restriction and modification, contains an endonuclease that inactivates in vitro biological activity DNAs lacking strain-specific modification. This specific has been purified to near homogeneity by a procedure includes DNA-agarose chromatography. highly enzyme requires ATP Mg2+ for is stimulated S-adenosylmethionine. The seems cleave DNA at well-defined sites, since it produces pattern bands upon agarose gel electrophoresis. no ATPase...

The mom gene of bacteriophage Mu encodes an enzyme that converts adenine to N6-(1-acetamido)-adenine in the phage DNA and thereby protects viral genome from cleavage by a wide variety restriction endonucleases. Mu-like prophage sequences present Haemophilus influenzae Rd (FluMu), Neisseria meningitidis type A strain Z2491 (Pnme1) H. biotype aegyptius ATCC 11116 do not possess Mom-encoding gene. Instead, at position occupied they carry unrelated protein with homology N6-methyltransferases...

Neisseria gonorrhoeae strains WR302 and PGH3-2 were characterized with respect to their restriction-modification phenotype. DNA was cleaved by HaeIII, indicating the lack of methylation at GGCC sequence. produced NgoSI (an isoschizomer NgoII). a restriction enzyme recognition sequence different from that NgoI, NgoII, or NgoIII. Plasmid pFT180 isolated unable transform PGH3-2, whereas plasmid able very high frequency. When methylated in vitro meth M. this PGH3-2. restrict vitro, it incapable...

Abstract Background Bioinformatic analysis of the genome sequence Neisseria gonorrhoeae revealed presence nine probable prophage islands. The distribution, conservation and function many these sequences, their ability to produce bacteriophage particles are unknown. Results Our genomic FA1090 identified five regions (NgoΦ1 – 5) that related dsDNA lysogenic phage. genetic content sequences were examined in detail found contain blocks genes encoding for proteins homologous responsible phage DNA...

Neisseria gonorrhoeae is the etiological factor of sexually transmitted gonorrhea disease that may lead, under specific conditions, to systemic infections. The gonococcal genome encodes many Restriction Modification (RM) systems, which main biological role defend pathogen from potentially harmful foreign DNA. However, RM systems seem also be involved in several other functions. In this study, we examined effect inactivation N. FA1090 ngo0545 gene encoding M.NgoAX methyltransferase on global...

Abstract Bacterial-bacterial interactions play a critical role in promoting biofilm formation. Here we show that NagZ, protein associated with peptidoglycan recycling, has moonlighting activity allows it to modulate accumulation by Neisseria gonorrhoeae . We characterize the biochemical properties of NagZ and demonstrate its ability function as dispersing agent for biofilms formed on abiotic surfaces. extend these observations cell culture tissue explant models nagZ mutants, human tissues...

As a result of frameshift mutation, the hsdS locus NgoAV type IC restriction and modification (RM) system comprises two genes, hsdS(NgoAV1) hsdS(NgoAV2). The specificity subunit, HsdS(NgoAV), product gene, is naturally truncated form an archetypal subunit (208 N-terminal amino acids instead 410). presence homonucleotide tract seven guanines (poly[G]) at 3' end gene makes strong candidate for phase variation, i.e., stochastic addition or reduction in guanine number. We have constructed...

ABSTRACT We constructed a phagemid consisting of the whole genome Neisseria gonorrhoeae bacteriophage NgoΦ6 cloned into pBluescript plasmid derivative lacking f1 origin replication (named pBS::Φ6). Escherichia coli cells harboring pBS::Φ6 were able to produce biologically active phagemid, NgoΦ6fm, capable infecting, integrating its DNA chromosome of, and producing progeny phagemids in, variety taxonomically distant Gram-negative bacteria, including E. , Haemophilus influenzae sicca...

We have constructed derivatives of Escherichia coli that can be used for the rapid identification recombinant plasmids encoding DNA restriction enzymes and methyltransferases. The induction DNA-damage inducible SOS response by Mcr Mrr systems, in presence methylated DNA, is to select strains E. we are temperature-sensitive systems been further modified include a lacZ gene fused damage-inducible dinD locus . detection methyftransferases simple, one step procedure based on at restrictive...

All Neisseria gonorrhoeae strains whose DNA sequences have been determined possess filamentous phage sequences. To ascertain if encoded proteins could form the basis of a gonococcal vaccine, rabbits were orally infected with S. enterica Typhimurium strain χ3987 harboring phagemid NgoΦ6 fm. The elicited sera contained large quantities anti-phage IgG and IgA antibodies that bound to surface N. cells, as shown by indirect fluorescent analysis flow cytometry. was able bind several proteins. also...

At least three restriction systems that attack DNA containing naturally modified bases have been found in common Escherichia coli K-12 strains. These are McrA, McrBC, and Mrr. A brief summary of the genetic phenotypic properties so far observed laboratory strains is set forth, together with a proposed nomenclature for describing these properties.

Three DNA methyltransferases, M NgoAI, and NgoBI NgoBII, free of any nuclease activities were isolated from Neisseria gonorrhoeae strains WR220 MUG116 respectively. NgoAI recognizes the sequence 5′ GGCC 3′ methylates first cytosine on both strands. M.NgoBII recognize TCACC GTAN5CTC NgoBII only one strand to produce GTAN5mCTC 3′.

The inner core of neisserial lipooligosaccharide (LOS) contains heptose residues that can be decorated by phosphoethanolamine (PEA). PEA modification II (HepII) occur at the 3, 6, or 7 position(s). We used a genomic DNA sequence lpt3, derived from Neisseria meningitidis MC58, to search N. gonorrhoeae FA1090 and identified homolog lpt3 in gonorrhoeae. A PCR amplicon containing was amplified F62DeltaLgtA, cloned, mutagenized, inserted into chromosome strain producing F62DeltaLgtAlpt3::Tn5. LOS...

Methyltransferases associated with type III restriction-modification (RM) systems are phase-variably expressed in a variety of pathogenic bacteria. NgoAXP, the RM system encoded by Neisseria gonorrhoeae, was characterized this study. The cloned resngoAXP and ngoAXPmod genes were Escherichia coli strains. restriction modification activities NgoAXP confirmed vivo lambda phage test vitro methylation DNA substrates presence [methyl-(3)H]AdoMet. As all known systems, activity needed both genes,...

All Neisseria gonorrhoeae strains whose DNA sequences have been determined possess filamentous phage representing their full genomes. The presence of in all sequenced N. suggest that purified particles might be used as a gonococcal vaccine. To test this hypothesis, we NgoΦfil phages and immunized rabbits subcutaneously. elicited sera contained large quantities anti-phage IgG IgA antibodies bound to the surface cells, shown by ELISA flow cytometry. structural NgoΦ6fil proteins present cells....

HP1 is a temperate bacteriophage, belonging to the Myoviridae family and infecting Haemophilus influenzae Rd. By in silico analysis molecular cloning, we characterized lys hol gene products, present previously proposed lytic module of phage. The amino acid sequence product revealed presence signal-arrest-release (SAR) muraminidase domains, characteristic for some endolysins. endolysin was able induce lysis on its own when cloned expressed Escherichia coli, but new phage release from infected...